Unfortunately, National Geographic seems to go further into the direction of poorly researched fiction rather than science. They now postulate that terraforming Mars is possible by erecting large mirrors in order to melt the polar ice caps. Call me annoyed.

Caption: Still image from National Geographic’s ‘MARS’ Season 2 Episode 1.

I will not address the recent study by Jakosky & Edwards (2018) here, which suggests that there isn’t enough carbon dioxide on Mars (I don’t think this study is conclusive by the way). My issue with National Geographic however lies in a completely different point:

The obvious flaw of the new episode is this: A melting operation would work very slowly and what happens if you start melting a limited amount of carbon dioxide at one place is that the excess carbon dioxide in the atmosphere would simply condensate and deposit back into the ice caps at a different place following a simple atmospheric equilibrium.

For the process to become a positive feedback cycle where more carbon dioxide heats the atmosphere and thus sublimates yet more carbone dioxide ice, you need to exceed a certain threshold level, in other words an initial kick to start a runaway feedback cycle.

On a global scale, the threshold level to actually start such a feedback cycle is enormous (keep in mind that Mars only gets half the sunlight per surface unit that Earth gets). As a matter of fact I’m not even sure if detonating nukes over the poles as Elon Musk once suggested in an off-the-cuff remark would do the trick.

Caption: Still image from National Geographic’s ‘MARS’ Season 2 Episode 1.

Consider that millions of square kilometres of carbon dioxide ice would have to be melted off ideally at once at a thickness of up to 8 metres (25 feet). You would need tens of thousands of very powerfull nukes to achieve that. There’s a lot of latent energy needed to transform ice to liquid and liquid to gas, especially when you are talking about uncounted millions of tons of it.

To a human, a nuke might seem like the ultimate in power but compared to mother nature, it is actually rather puny. Let me illustrate this as follows: The largest nuke ever built was the soviet Tsar Bomba with a yield equivalent to 100 megatons of TNT. In comparison, a meteor measuring 1 cubic kilometre (0.6 by 0.6 by 0.6 miles) coming in at orbital speed caused by the accelaration in Earth’s gravity field will unleash the energy of 1’000’000 Tsar Bombas. I believe that could possibly do the trick.

Now to be honest, I don’t know where the treshold level for starting a terraforming feedback cycle is. However, if you consider the orders of magnitudes between the three mentioned possibilities (mirrors, nukes and asteroids) you don’t need to be a genius to come to the conclusion that the mirror scheme is extremely unlikely to work - to put it mildly.

If National Geographic had been serious about this series and its viewers and actually done their homework, they could have easily arrived at that conclusion. Which is the reason why I am rather annoyed at it.

Caption: Still image from National Geographic’s ‘MARS’ Season 2 Episode 1.

(Oh and by the way, here’s a P.S.: once you got a warm atmosphere and liquid water and you start to release cyanobacteria to produce oxygen, the photosynthesis will take carbon dioxide back out of the atmosphere, so if you don’t resupply it, the whole process goes back to where it started - a frozen, airless planet. Terraforming is not impossible - but it’s a whole lot more complex than certain people understand.)

Octafluoropropane would be a gas on Mars; it’s basically a short chain (3 carbon molecules of) teflon. It is heavy and wont be driven off by solar wind quickly. It is inert and non reactive at lower temperatures (below combustion point of most fuels). It must be manufactured, but is simple to produce locally. It could go a long way to magnifying CO2’s greenhouse effect (provided we interconvert CO2 into C3F8).

Additionally, a continuous bombardment of comets or asteroids around the poles could provide both heat and additional volatiles for Mars’s atmosphere. Indeed this idea was floated long before nukes. It would require decades of fore-planning and scouting to find and redirect objects towards Mars. Since much of the infrastructure is likely to be underground, any people living on Mars would be minimally affected (except perhaps for solar power generation). Thus, a sufficient baseline load of nuclear power would be needed before bombardment could begin.

P.S.
The Ort Cloud would be great place to find icy rocks to send to Mars. Especially since that’s probably where Mars’s old atmosphere wound up being blown to.

Somehow National Geographic’s products was related with education, science, documentary…etc. But “Mars” series is a lame one. They did not employ scientific advisers or did not listen them at all.NG “Mars” series intro
“Ron Howard said it’s not fiction it’s all very much based on a research…”. Hmm…Scientific series? It’s not even funny, it’s a lame.

The thought of slamming icy rocks into Mars seems like a highly inefficient use of, and waste of resources necessary for the survival of humans in space. Such resources are best mined and refined in space for every bit of gas and minerals and slag while still in space.

As for the National Geographic series Mars; I like it. Sure it has its flaws, but anything that promotes space exploration and colonization is a net good.

Well, as I tried to explain it might be the only thing radical enough to work but of course you’re right that just now we simply don’t have the means and can’t spare the ressources to do it.

When I think of terraforming Mars I always have the year 2100 in mind as earliest date to even try to start such a process. That includes certain assumptions on technologies and capabilities that are reasonable to assume available at the end of this century:

Fusion reactors, massively more powerfull ion drives, carbon nanotube ropes (e.g. for space elevators) and a huge space based economy to name just a few.

I think suggesting to start terraforming as soon as the first humans are on Mars in the 2030ies is simply not realistic: As I tried to show, initializing the process can not be achieved in a gradual manner. Thats my main gripe with the first episode.

As for the National Geographic series Mars; I like it. Sure it has its flaws, but anything that promotes space exploration and colonization is a net good.

Fine. For entertainment purpose fine. As a sci-fi, fantasy and drama cocktail its fine. But they claim its science and research based series. And it’s on National Geographic channel. It makes me angry. Maybe that’s my problem. :)

But anyway. JohnnySpacer You have a knowledge. More or less You are related with space science and knowledge. And sure You can see it’s flaws and not take some false things as science facts. But most peoples can’t. An hey they sad it’s science and research based series…that’s science facts then, right?. So We can terraform mars with huge mirrors, we can talk with spaceships which are half away from mars in real time communication, we sure want to build habitats with doors which upon opening the entire base is momentarily airless. Or astronauts which for each occasion use parts of their body but not tools to fix some tech. problems, pregnancy…etc, etc. And that’s research based. Come on.
Some people will take such a movie seriously. And at the end more harm can be done than good.

JohnnySpacer:

…but anything that promotes space exploration and colonization is a net good.

I did not agree with that statement. “Anything” can’t be net good. Sorry.

On the other hand, you’ve also got a group of scientists who grew up watching the ridiculousness of talking carrots on Lost in Space which inspired them into the field. Apparently, it doesn’t have to make sense to make people want to pursue something that does.

That’s right. Some grown up with that and became scientists… And I do not want to say that comedy, parody or even fantasy can not inspire the next generation to become scientists (for example Orville). But not “anything”.
And if You claim that your film(series) is very much based on research and science. But in fact is very false and misleading. This is a completely different case. We often do not appreciate the media seriously enough. This is a very powerful training and information tool. Often it can cause damage, serious damage.
Well ok, I can label it as a comedy-parody-drama whatever. It’s ok then. But it’s on the National Geographic.

Yeah, That’s right. Average citizen don’t care bout specific science facts. But on the other hand if they don’t care about science facts then probably they don’t care about colonizing mars. Maybe not.
And who says that colonization of mars is possible? NG ? Well okay, at least in theory we can. But is it real in practice? There are huge bunch of things that kicks in here. Turns out the most important thing will be how many people wants to colonizing mars at all. Does this series affect that? Maybe…
p.s. National Geographic was one of my education sources. That’s why I was so annoyed.